Chlorination Barrel (End Section)
The chlorination process in gold extraction employs large vats or revolving barrels, the material inside of which is moistened with water and treated with chlorine gas to form a solution of Gold Chloride. This is then run off, and the gold precipitated, usually by means of Ferrous Sulphate or charcoal.
John H. Finley ed. Nelson's Perpetual Loose-Leaf Encyclopaedia (vol. 5) (New York, NY: Thomas Nelson and Sons, 1917) 479